DE2550852A1 - ANTIOXIDIZER - Google Patents

Description

1'ATfNIANWALTE

DR.-I NG. H. Fl NCKE DIPL.-ING. H. BOHR DIPL.- ING. S. STAEGER

Telephone: "26 60 60 Teiegromme- Claim» Munich Postal check accounts Munich 270 44

Bank details Boyer. Vereintbank Munich, account 620 404

mopp.no. 23870 - Dr.K / H.

Please indicate in the answer

ICI CASE NO. Z / Dr 27449

8 MUNICH S ₁

Garbage Tritraö · 31

1 2nd NOV. 1975

IMPERIAL CHEMICAL INDUSTRIES LIMITED

Imperial Chemical House,

Millbank

London S.W.1 / GREAT BRITAIN

"Antioxidant"

PRIORITY:

Brit. Patent application No. 50915/74 dated November 25, 1974

The invention relates to antioxidants and in particular to the use of N-substituted diphenylamines as antioxidants.

According to the invention there are compositions stabilized against oxidation proposed that an organic material sensitive to oxidation and an N-substituted one in an effective amount Diphenylamine of the formula:

609822/0905

NO

(D

contain, in which the group R for alkyl rait two or more carbon atoms, Aralkyl, alkenyl, cycloalkyl or aryl, all of which can be substituted, methyl or a group of Formula:

,1

κ ² .

R ³ and R ⁴ ,

and the groups R,

can be different for H, NC ^, NH aikylamino, alkyl or alkoxy.

which same or

2 1 aikylamino, di-

Examples of the group R, if it is alkyl, are ethyl, n-propyl, isopropyl, η-butyl, sec-butyl, isobutyl, tert-butyl, hexyl, 2-ethylhexyl, tert-octyl, dodecyl or octadecyl.

Examples of the group R, if it is substituted alkyl, are 2-ethoxyethyl, 2- (hydroxyethoxy) ethyl, 2-hydroxyethyl, 2-methoxyethyl, 2-cyanoethyl, 2- (hydroxyethylthio) ethyl or 3-hydroxypropyl.

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Examples of the group R when it is aralkyl, are benzyl, 4-methylbenzyl, diphenylmethyl or triphenylmethyl.

Examples of the group R when it is substituted aralkyl are 4-methoxybenzyl, p-nitrobenzyl or p-bromobenzyl.

Examples of the group R, if it is alkenyl, are vinyl, allyl, isopropenyl or 2-methylallyl.

Examples of the group R when it is substituted alkenyl are 2- (cyclohexyl) vinyl or 2-chlorovinyl.

Examples of the group R, if it is cycloalkyl, are cyclopentyl, cyclohexyl or 4-methylcyclohexyl.

An example of the group R when it is substituted cycloalkyl is 4-methoxycyclohexyl.

Examples of the group R when it is aryl are phenyl, 2-, 3- or 4-tolyl, 2-, 3- or 4-ethylphenyl or naphthyl.

Examples of the group R when it is substituted aryl are 2-, 3- or 4-methoxyphenyl, 3-methyl-4-methoxyphenyl, 4-aminophenyl, 4- (methylamino) -phenyl and 4-CDimethylamino) phenyl.

Examples of the group R when it is a group of the formula

609 8 22/0 9 05

These are N-diphenylamino, N-4-methyldiphenylamino, N-4,4 · -Dimethyldiphenylamino, N-4-Methoxydiphenylamino, N-4-methyl-4 ^l -methoxydiphenylamino or N-4,4'-DimethOxydiphenylamino. ;

Examples of the groups R ¹ , R ² , R ⁵ and R ⁴ are H, NO ₂ , NO, NH ₂ , methyl, ethyl, T- and 2-propyl, methoxy, ethoxy, isopropoxy, methylamine, isopropylamino or dimethylamino.

3 4 In the connection where R and R are present, i.e.

λ ρ 3 when R is a diphenylamino group, where R, R, R and

R can all be different, it is often preferred that R ¹ and R ^{5 are the} same and R and R ^{4- are the} same.

Preferred compounds of formula (1) are those in which R is triphenylmethyl, allyl or lower alkyl, i. Is alkyl of 1 to 4 carbon atoms, especially methyl.

12th
Preferred groups R and R are H or amino, C., -Alkylamino * di- (C. .. -alkyl) -amino, C. .. -alkyl or CL. -Alkoxy. It is also preferred that R is H or R and that

ρ
R is a group derived from available petrochemical olefins, especially Höptyl and Octyl and most especially tert-octyl.

Examples of compounds of formula (1) are N-ethyl-4-propyl-diphenylamine, N-ethyl-4-ethoxy-4'-n-butyl-diphenylamine, Nn-propyl-4,4 ^l- diisopropyl -diphenylamine, N-methyl-4-

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tert-octyl-diphenylamine, N-methyl-4,4'-di-tert-octyldiphenylamine, N-ethyl-4-isopropoxy-diphenylamine, Nn-butyl-4-n-butoxy-diphenylamine, Nn-propyl-4 -sec.-butoxy-4 '- (1,1,2-trintethylbutyl) -diphenylamine, N-methyl-4-amino-diphenylamine, N-methyl-4-methylamino-4'-ethyl-diphenylamine, N-methyl- 4-dimethylamino-diphenylamine, N-ethyl-4-ethylmethylamino-4 ^l -methoxy-diphenylamine, N-methyl-4-propylamino-4 ^l -ethoxy-diphenylamine and N-methyl-4-n-butylaminodiphenylamine.

The preferred compound of the formula (1) is to be tetraphenylhydrazine, N-methyldiphenylamine, N-methyl-4-ethoxydiphenylamine, N-methyl-4-methyl-4'-methoxydiphenylamine, N- (triphenylmethyl) diphenylamine and N-allyldiphenylamine are mentioned will.

Particularly preferred compounds are said to be N-methyl-4-ethoxydiphenylamine, N-methyl-4-methyl-4'-methoxydiphenylamine and tetraphenylhydrazine can be mentioned.

The compounds of formula (1) which are often known can be obtained by conventional methods. if for example, R represents a hydrocarbon radical, a diphenylamine compound or an alkali metal salt of which are reacted with a hydrocarbon halide, in particular chloride or bromide. When R for a group of the formula

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~ ⁶ ~ 2 5508

stands, then the compounds of the formula (1 «) ibei-i can be obtained, for example, by using diphenylamine - * - n compounds with an oxidizing agent such as »potassium permanganate, oxidized. In this case it may be necessary to protect groups sensitive to oxidation. ' For example, if one of the groups R, R, R ^ or R an aminog-ruipse ^ _ then this can be acylated, for example with acetic anhydride, before the oxidation is carried out whereupon the amino groups are then regenerated after oxidation.

The organic oxidation-sensitive material can be fat or oil, but is in particular a polyolefin, for example a polyolefin, for example polyattyls, polypropylene, poly (4-methylpentene-1) or a mixed polymer thereof with smaller amounts of other ethylenic unsaturated compounds, such as For example, pentene-1 and decene "iV eliniatäie" - res polymer of ethylenically unsaturated veins. such as methyl methacrylate, vinyl chloride, acrylonitrile vinylidene chloride and vinyl acetate, or especially '© iru natural rubber or a synthetic rubber such ^ ^".B! . * A polymer of butadiene or isoprene or a Mischpoly. ^ Mer, of butadiene or isoprene with styrene, Acryloftitrii. Methyl methacrylate or another polymerized monomer, or of butylene with a conjugate of ethylene, propylene and a diolefin.

The compound of the formula (1) can be converted into the organic material incorporated in every conventional way. For example, it can be mixed with the solid polymer in chip form or in finely divided form, or a? with the polymer, for example unvulcanized rubber, incorporated on a mill or the polymer in solution

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in a solvent, which is then evaporated, be admitted;

In the case of rubbers, the compound of formula (1) expediently together with the rubber in unvulcanized form with other compounding ingredients, e.g. Accelerators, Vulkanisatiönsmittel ·, fillers and pigments, mixed, whereupon the unvulcanized The rubber composition is vulcanized, for example by heating, until a stabilized vulcanizate is formed is.

The amount of the compound of the formula (1) is expediently between 0.1 and 5% by weight, and preferably between 0.5 and 2.0 wt * - # based on the rubber.

Rubber vulcanizates can be obtained that are both good Heat aging and flex cracking properties and also have good resistance to oxidation (for example in oxygen absorption and oxygen bomb tests).

The method of incorporating the compound of the formula (1) in the oxidation-sensitive organic materials, the unvulcanized rubber composition, the stabilizing Containing amounts of the compound of formula (1), the process for vulcanizing the! vulcanized, stabilized Rubber composition and the stabilized vulcanizate represent further aspects of the invention.

The invention is illustrated in more detail by the following examples, wherein parts and percentages are expressed by weight.

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Examples 1 to 4

A gum base, the composition of which is specified in more detail below, is prepared by the Mix ingredients together in a BR size Banbury mixer .

Parts by weight

Natural rubber (SMR 5) 100.

Zinc oxide 3.5

Stearic acid 3.0

N 330 (furnace black with high abrasion) 45.0

aromatic processing oil 3.5

N-Cyclohexyl-benzthiazyl-sulfenamide 0.5

Sulfur 2.5

At various portions of the masterbatch, various N-substituted diphenylamines which are shown in Table I, separately in a dosage of 1.0 parts / 100 parts of rubber incorporated in a laboratory mill at 70 ⁰ C. Test pieces are cured 20 min. At 153 ⁰ C. The resistance to aging of the vulcanized blends is then determined by oven test at 100 ⁰ C. Sauerstoffaufnähmetestsbei 90 ⁰ C are also performed and the results a ^ ler these tests are given in Table I below. _;

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TABLE I.

Example No. Antioxidant

nothing

N-methyldiphenylamine

N-methyl-4-

ethoxy-di-

phenylamine

N-methyl-4-N- (triphenylmethyl-4'-methyl) -dimethoxydiphenylamine phenylamine

Unaged tensile strength (MN / m ² )

Aged

% Retained tensile strength after aging at 10O ⁰ C

while
Il 16 Hours. until to 1 p Il
Il 48
72 H i on Oxygen uptake at
90 ⁰ C hours
would take

28.8

58
38
24
15th

28.4

70 48 37 21

15th

26th

28.6

83
66
63
23

26th

cn cn O OO

example

A gum base is prepared as in Examples 1-4. Tetraphenylhydrazine is added to a portion of this basic mixture added in a dosage of 1.0 part / 100 parts of rubber on a laboratory mill at 70.degree.

A Mconey Viscometer test is carried out and the results given in Table II are obtained. The test pieces are cured 20 min. At 153 ⁰ C and then tested for their resistance to aging by oven test at 10O ⁰ C. Resistance to flex cracking is measured by the De Mattia test. The results of these tests are also given in Table II.

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TABLE II

Anti-oxidants

Mooney scorch at 120 ⁰ C minutes to (min. +10 units) Nothing tetraphenyl · hydrazine

27

20th

cn
ο
co

Tensile strength after vulcanization during 20 min. At 153 ⁰ C (m / m ²⁾

$ 6 Retained tensile strength after aging at 100 ^° C

during: 16 hours 30 hours 48 hours 72 hours 96 hours

De Mattia bending test

Cycles up to Level C Cycles up to Level D Cycles up to Level E Cycles up to Level P. 28

28.2

61 • 000 84 I. ro 45 000 73 cn 33 ooo 62 cn 16 000 37 CD 14th 26th CO 29 90,000 cn 37 115,000 ro 44 144,000 52 180,000

Claims (13)

PATENT CLAIMS 1. Compositions that stabilize against oxidation are, characterized in that they are made of an oxidation-sensitive organic material and an effective amount of an N-substituted diphenyl amine the formula: (D consist, wherein the group R for alkyl with 2 or more Carbon atoms, aralkyl, alkenyl, cycloalkyl or aryl, all of which may be substituted, methyl or a group of the formula: 609822/0905 1 2 ^ 5 4 and R, R, R and R, which can be identical or different, _{stand for H, NO 2} , NH, alkylamino, dialkylamino, alkyl or alkoxy. 2. Compositions according to claim 1, characterized in that R is triphenylmethyl, allyl or C ^ .- alkyl. 3. Compositions according to claim 2, characterized in that R is methyl. 4. Compositions according to one of claims 1, 2 or 3, 1 2 characterized in that R and R are identical or different and stand for H, amino, C ..- alkylamino, di (C _1. -alkyl) amino, C _1. -alkyl or C _1. -alkoxy. 5. Compositions according to one of claims 1, 2 or 3, 1 2 characterized in that R stands for H or R, and R ^{2 represents} heptyl or octyl. 6. Compositions according to claim 5, characterized 2
indicates that R stands for tert-octyl. 7. Compositions according to one of claims 1, 2 or 3, characterized in that R, R, R and R, which can be the same or different, represent H, NO ₂ , methyl, ethyl, 1- or 2-propyl, methoxy , Ethoxy, isopropoxy, methylamino, isopropylamino or dimethylamino. 609822/0905 8. Compositions according to claim 1, characterized in that the compound of formula (1) from tetraphenylhydrazine, N-methyldiphenylamine, N-methyl-4-ethoxydiphenylamine, N-methyl-4-methyl-4 ^f -methoxydiphenylamine, N- (triphenylmethyl ) -diphenylamine or N-allyldiphenylamine ". 9. Composition according to claim 1, characterized in that the oxidation-sensitive organic Material made of natural or synthetic rubber ". 10. The composition according to claim 9, characterized in that the rubber is in unvulcanized form is present and contains rubber compounding ingredients. 11. Composition in the form of a vulcanized rubber, characterized in that it is by heating a The composition of claim 11 has been prepared at vulcanization temperatures. 12. Composition according to claim 10 or 11, characterized in that that the amount of the compound of the formula (1) is 0.1 to 5% by weight based on the rubber. 13. The composition according to claim 12, characterized in that the amount of the compound of formula (1) 0.5 to 2 wt .- #, based on the rubber. PÄteiTANWÄU * . H. FlNCKE, DIPL-ING. OiPL-INO. S. STAK » 809822/0905